--google-use-existing: Don’t create a new VM, use an existing one. This is useful when you’d like to provision Docker on a VM you created yourself, maybe because it uses create options not supported by this driver.

--google-use-internal-ip-only: When this option is used during create, the new VM is not assigned a public IP address. This is useful only when the host running docker-machine is located inside the Google Cloud infrastructure; otherwise, docker-machine can’t reach the VM to provision the Docker daemon. The presence of this flag implies --google-use-internal-ip.

--google-use-internal-ip: When this option is used during create, docker-machine uses internal rather than public NATed IPs. The flag is persistent in the sense that a machine created with it retains the IP. It’s useful for managing docker machines from another machine on the same network, such as when deploying swarm.

Google Compute Engine supports image families.
An image family is like an image alias that always points to the latest image in the family. To create an
instance from an image family, set --google-machine-image to the family’s URL.

The following command shows images and which family they belong to (if any):

gcloud compute images list

To obtain a family URL, replace <PROJECT> and <FAMILY> in the following template.